1. Field of the Invention
The invention relates to a device and a method for determining a portion of a battery characteristic curve.
2. Description of Prior Art
Energy management in motor vehicles is becoming increasingly significant. The cause is the increasing electrification, that is to say an increased number of electrical devices and loads that have to be supplied with energy. This energy is made available, inter alia, by the vehicle battery. In addition, the individual loads have different priorities in terms of their supply. For example, it is necessary to ensure that safety-related loads are supplied with energy; these include the brakes, the lighting system and airbags. In order to ensure the energy supply of safety-related loads, it is necessary to detect and monitor continuously the state and/or the characteristic variables of the vehicle battery.
An important state variable of the vehicle battery is the state of charge (SOC). A further characteristic variable of the vehicle battery is often referred to as the open circuit voltage (OCV). The state of charge of the vehicle battery can be obtained with this open circuit voltage. To do this, a characteristic OCV/SOC battery characteristic curve can be used. It has been found that a uniform characteristic curve can be used for a large proportion of the batteries of European manufacturers such as, for example, Banner, Exide, and JCI. This OCV/SOC characteristic curve for batteries of European manufacturers is different from the characteristic curves of batteries of manufacturers from other continents, in particular from batteries of Asian manufacturers.